Pyrometer



(Ho-Model.)

E. BROWN.

Pyrometer.

No. 234,168. Patented Nov. '9, I880.

NFETERS. PHOTOL|THOGRAPHER. WASHINGTON. D c.

UNITED STATES PATENT OFFICE...

EDWARD BROWN, OF PHILADELPHIA, PENNSYLVANIA.

PYROM ETER.

SPECIFICATION forming part of Letters Patent No. 234,168, dated November 9, 1880.

Application filed May 6, 1880.

To all whom it may concern:

Be it known that I, EDWARD BROWN, of Philadelphia, Pennsylvania, have invented a new and useful Hot-Blast Pyrometer for Iron- Furnaces, of which the following is a specification.

Pyrometers made on the plan of the original Gauntlett with the stem of difl'erent materials, usually metals, having a different quality of expansion, are soon injured when fixed in the main pipe and constantly exposed to a red heat. The temperature of the hot-blast since the introduction of regenerative firebrick stoves is now generally above red heat.

The object of my invention is to make the pyrometers at present in use more durable and available for testing higher temperatures.

It consists in securing to the hot-blast main a branch pipe freely open to the hot-blast at its lower end and closed at the upper end. This pipe has a valve at its upper end, by which the blast is allowed to escape from the pipe and thereby bring the full temperature of the blast upon the expansion-stem of the pyrometer, which is inserted within the branch pipe. By this arrangement of parts the temperature of the blast upon the pyrometer may be maintained as high as the pyrometer will constantly bear without much injury, and then by opening the valve the full temperature is brought upon it for a few seconds only when taking an observation.

The figure is a sectional elevation.

B is the hot-blast main pipe, lined with firebrick. A saddle or flange, U, is bolted on the main pipe, and to it is screwed the branch pipe D. This is closed at the top and a pyrometer, E, inserted, its expansion-stem e being within the branch D. A valve, H, is screwed into the top end of the pipe D, which is opened occasionally when an observation is desired. The opening of this valve must be sufficiently large to permit a rapid escape of (No model.)

the air, or the temperature in the branch D cannot be raised to the true temperature.

d is an outside casing to protect the pipe D from sudden atmospheric changes.

In mypatent ofMay, 1877, avalve is shown to admit the blast upon the expansion-bar of a pyrometer. There is, however, a material advantage in the present invention over that one.

The pipe D being freely open at its lower end, the expansion-bar 6 may, by direct radiation and contact of the blast, be maintained at or about 900, just about dull-red heat. Then, by opening the cock H, the full current of the hot-blast passes up,and in two or three minutes a temperature of 1200 or 1400 is indicated.

A small escape-hole may be made at h, or the cock be always open a very little to raise the temperature within the pipe D.

Fixed pyrometers, which have a stem, 0, consisting of a tube inclosing a bar of some other material, only indicate ,correctly when both are at the same temperature. This requires five to fifteen minutes when the valve intervenes between the blast and the expansion-stem. The presenti 'ention obviates this and permits ot'an ac ate indication in a much shorter time, and is practically far more useful. This position of the valve also permits of the fixed pyrometer being tested at any time by my portable pyrometer.

I claim In a hot-blast pyrometer, the combination of the hot-blast main B, the branch pipe D, open to the main at its lower end and closed at the top, and a valve atthe top end to bring the current of the blast upon the expansion-bar within the branch pipe, substantially as described.

Witnesses:

J OHN F. GRANT, D. LOUIS SHIvERs.

EDVVD. BROWN. 

